tim@129: /* Copyright (C) 2007 con terra GmbH (http://www.conterra.de)
tim@129:  * All rights reserved
tim@129:  *
tim@129:  * $Id: Datasource.java,v 1.4 2008/01/30 12:38:34 blume Exp $
tim@129:  *
tim@129:  * created by:      drewnak
tim@129:  * created at :     21.11.2007
tim@129:  * created at :     14:25:50
tim@129:  *
tim@129:  * modified by:     $Author: blume $
tim@129:  * modified at:     $Date: 2008/01/30 12:38:34 $
tim@129:  */
tim@129: package de.intevation.gnv.geobackend.sde.datasources;
tim@129: 
tim@129: import java.util.Map;
tim@129: 
tim@129: import de.intevation.gnv.geobackend.sde.datasources.exception.DatasourceException;
tim@129: 
tim@129: /**
tim@129:  * Abstract class for handling different datasources.
tim@129:  * This method provides a static method for creating dataosurce objects.
tim@129:  *
tim@129:  * @author drewnak
tim@129:  */
tim@129: public abstract class Datasource {
tim@129: 
tim@129:     protected Map mParameters;
tim@129: 
tim@129:     protected String mName;
tim@129: 
tim@129: 
tim@129:     /**
tim@129:      * Triggers the creation of a dataosurce object. Following the guidelines, the parameters for creating this datasource are delivered by the configuration file.
tim@129:      *
tim@129:      * @param pName      a name for the datasource.
tim@129:      * @param pClassname The name of the class extending this abstract datasource class. Used to create a new instance.
tim@129:      * @param pParams    a Map of Parameters needed for the initialization of the datasource.
tim@129:      * @return a datasourceobject
tim@129:      * @throws DatasourceException if the class could not be found or the initialization of the datasource fails.
tim@129:      */
tim@129:     public static final Datasource create(String pName, String pClassname,
tim@129:                                           Map pParams) throws DatasourceException {
tim@129:         Class lDatasourceClass;
tim@129:         try {
tim@129:             lDatasourceClass = Class.forName(pClassname);
tim@129:         } catch (ClassNotFoundException e) {
tim@129:             throw new DatasourceException("Could not load class " + pClassname);
tim@129:         }
tim@129:         Datasource lNewInstance;
tim@129:         try {
tim@129:             lNewInstance = (Datasource) lDatasourceClass.newInstance();
tim@129:         } catch (Exception e) {
tim@129:             throw new DatasourceException("Could not create instance of " + pClassname, e);
tim@129:         }
tim@129:         lNewInstance.init(pName, pParams);
tim@129: 
tim@129:         return lNewInstance;
tim@129:     }
tim@129: 
tim@129:     /**
tim@129:      * An abstract method for the initialization of a datasource instance.
tim@129:      * Of course, only the concrete implementation knwos about the ncessary parameters for the initialization.
tim@129:      *
tim@129:      * @param pName   a name for the datasource.
tim@129:      * @param pParams a Map of Parameters needed for the initialization of the datasource.
tim@129:      */
tim@129:     protected abstract void init(String pName, Map pParams) throws DatasourceException;
tim@129: 
tim@129:     /**
tim@129:      * @return
tim@129:      */
tim@129:     public String getName() {
tim@129:         return mName;
tim@129:     }
tim@129: 
tim@129: 
tim@129:     /**
tim@129:      * This method returns a datasourceconnection.
tim@129:      * Only the concrete implementation of the Datasource knwos about the DatasourceConnection-Implementation to return.
tim@129:      *
tim@129:      * @return a DatasourceConnection
tim@129:      */
tim@129:     public abstract DatasourceConnection getConnection();
tim@129: 
tim@129:     /**
tim@129:      * Returns a DatasourceConnection. This method is usualy called after an executed query.
tim@129:      * See: Some datasource implementations need to explicitly close an existing connection.
tim@129:      *
tim@129:      * @param pConnection the connection to be returned.
tim@129:      */
tim@129:     public abstract void returnConnection(DatasourceConnection pConnection);
tim@129: }